In many types of industrial equipment, the components of the equipment are driven from a power source at specific speeds which are critical to the operation of the equipment. The type of power source and thereby the drive speeds available often depend on the power sources available at the location of the equipment and sometimes on the preference of the operator of the equipment. Diesel engines are a common type of power source, particularly for surface mining shovels equipment. Where the equipment is marketed worldwide as is typically the case of surface mining shovels and electrical power sources are used, the drive speeds available will be determined in part by whether the electrical power source frequency is 50 or 60 hertz.
The present approach to accommodating the differing drive power sources and speeds for surface mining shovels is to design the equipment so that its components receive the necessary speed drives from the power source that is available to the equipment at its intended operating site. Of course, individual designing of this nature is quite expensive. Moreover, where the equipment is designed to accept and operate from a single specific power source, it lacks the flexibility to be readily converted to operating from a different power source in the event that a different more desirable power source becomes available or the equipment is moved to a location requiring a change in power source.